Note: Descriptions are shown in the official language in which they were submitted.
CA 02714872 2010-09-13
WO 03/098087 PCT/US03/04493
DOWNHOLE OILFIELD TUBULARS HAVING LINERS
WITH DIFFUSION BARRIER LAYER
BACKGROUND
Tubular goods, such as oil country tubular goods ("OCTG's") (e.g., well
casing,
tubing, diillpipe, drill collars, and line pipe) and flowline tubular goods,
are often used for
transportation of gases, liquids, and mechanical equipment, including various
applications
related to extraction of petroleum and natural gas from underground
reservoirs, transportation
of petroleum, natural gas, and other materials, such as solution mining and
slurry transport
lines in the mining industry. OCTG's may be used to transport the product from
the
underground reservoir, and also to house mechanical equipment (e.g.,
artificial lift devices,
rod couplings, plungers, reciprocating rod pumping units, rotating progressive
cavity pumps,
and plunger lift units), electrical equipment (e.g., well monitoring
equipment), and/or
transport gases or liquids for disposal operations or secondary removal
operations. These
gases and liquids may contain corrosive materials such as, by way of example
only, salt
water, dissolved oxygen, CO2, or H2S. In addition, flowline tubular goods may
be used to
transport petroleum, petroleum products, natural gas, or other gases or
liquids from one point
to another. The gases and liquids which flow within flowlines may, comprise
corrosive
and/or abrasive components. In addition, flowline tubular goods may also
occasionally
require the use of mechanical equipment, such as pigs, to clean or service the
tubular good.
With respect to moving mechanical equipment and abrasive fluids, such as
reciprocating or rotating rods or pumps or drilling or mining slurries (e.g.,
drilling mud),
friction and abrasion may cause wear, fatigue, and even failure of the pipe
and/or the
equipment. In addition, this wear, fatigue, or failure may be accelerated due
to the presence
1
CA 02714872 2010-09-13
WO 03/098087 PCT/US03/04493
of corrosive or abrasive materials, such as, for example CO2, or by deviations
in the direction
of the well bore. One method of combatting this wear in oil well production
equipment is
disclosed in U.S. Patent No. RE36,362 to Jackson
In addition to the possible acceleration of mechanical wear, fatigue, and
failure, the
presence of corrosive material, in and of itself, may cause chemical damage to
the OCTG' s
and flowline tubular goods. By way of example only, the presence of CO2, when
contacted
with metal or other materials may cause corrosion, dusting, rusting, or
pitting, which may
lead to failure of the material. In addition, the presence of microbiological
active agents,
such as bacteria, may produce chemicals which influence or accelerate
corrosion.
It would therefore be desirable to create tubular goods which decrease or
eliminate the
mechanical and/or chemical wear, fatigue, or failure caused by the conditions
surrounding the
extraction of materials such as petroleum or natural gas and transportation of
materials,
thereby potentially increasing the life and productivity of the tubular good.
SUMMARY
Disclosed herein are methods and apparatus for reducing or eliminating the
mechanical and/or chemical wear, fatigue, and failure on tubular goods. The
methods
comprise disposing a liner along at least a portion of the tubular good. The
liner may
decrease friction, thereby decreasing mechanical wear as well as reducing the
amount of
energy necessary to operate the mechanical tool or pump the abrasive fluid. In
addition, the
liner may also comprise a material which is resistant to particular chemicals
or a barrier to
particular chemicals, thereby decreasing or eliminating contact between the
chemicals and the
tubular good and decreasing or eliminating the wear or corrosion caused by
those chemicals.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure I is a schematic drawing of a tubular good in accordance with
embodiments of
the present invention.
2
CA 02714872 2010-09-13
WO 03/098087 PCT/US03/04493
Figure 2 is a cross section of a tubular good in accordance with embodiments
of the present
invention.
Figure 3 is a rotating rod pumping system in accordance with embodiments of
the present
invention.
DETAILED DESCRIPTION
Referring now to Figure 1, there is shown metal tubing 30, coupling 36, and
liner 40. Two joints
of metal tubing 30, having an inner diameter 32 and outer diameter 34, are
connected together by
coupling 36. Disposed within each tubing joint 30 adjacent to its inner
surface 38 is a liner 40 (an
embodiment of which is shown in detail in Figure 2). Liner 40 may be a
multilayer system comprising
both a wear resistant material and a diffusion barrier. In some embodiments,
where gas diffusion is of
minimal or no concern, liner 40 may comprise a layer comprising only a wear
barrier such as
polypropylene with no diffusion barrier being present.
The liner 40 may be disposed within the tubing 30 by any one of several
methods known in the
art. One method of disposing the liner within the tubing bore is to provide a
polymer liner having an
outside diameter which is slightly greater than or equal to the inner diameter
of the tubing section pipe
having an outside diameter larger than the internal diameter of the tubing.
Reduce the outside of the liner
and insert the reduced diameter liner within the tubing. After the liner is in
place, it will attempt to
substantially return to its original shape and will become secured within the
tubing section via process
called plastic deformation. There may be numerous methods of reducing the
outside diameter of the liner
for insertion into a tubing section are available. For example, rollers may be
used to mechanically reduce
the outside diameter of the liner by the desired amount and to push the liner
into the tubing joint. Other
methods include pulling the liner through a sizing sleeve or orifice and
pushing the reduced diameter liner
into place in the tubing.
One method of disposing the polymer liners within the tubing sections includes
providing a liner
having an initial outside diameter similar to or larger than the inner
diameter
3
CA 02714872 2010-09-13
WO 03/098087 PCT/US03/04493
of the tubing, reducing the outer diameter of the liner by mechanical means
and inserting the
liner into the tubing bore. The ends of the polymer liner may then be softened
using a heat
source and formed around the end of the external pipe thread on the metal
pipe. In some
cases, the ends may be reinforced for additional structural integrity. The
ends may then be
joined onto a coupling (with or without an internal coating or corrosion
resistant insert) used
to join each stick of lined pipe. The process ultimately provides a one-piece
seamless liner in
each joint that is mechanically bonded to the metal pipe ID. The wall
thickness of the
claimed liners is preferably between about 2 and 10 millimeters. The diameter
of the claimed
liners may be between about 20 and 700 millimeters or greater. In the
embodiments shown
in Fig. 1, the thickness "t" of the liner 40 is about 4 millimeters.
Referring now to Figure 2 (not to scale), there is shown lined tubular good
100
comprising outer layer 110, diffusion barrier 120, adhesive layers 130 and 160
(optional), and
friction and wear reducing layers 140 and 150. outer layer 110 may be a metal
tubular good
such as an OCTG, a flowline tubular good, or a solution mining or slurry
transport line. The
tubular good liner is preferably comprised of elements 120, 130, 140, 150, and
160. Friction
and wear reducing layers 140 and 150 may comprise, by way of example only,
polyethylene
or polypropylene. Layers 140 and 150 may or may not consist of the same
material.
Diffusion reducing layer may comprise, by way of example only, a vinyl alcohol
such as
polyvinyl alcohol. Layer 140 may be bonded to diffusion barrier 120 by any
method as
would be appreciated by one of skill in the art. By way of example only,
layers 120 and 140
may be bonded by adhesive layer 130 and layers 150 and 120 may be bonded by
adhesive
layer 160. Adhesive layers 130 and 160 may be, but are not necessarily, the
same adhesive.
Adhesive layers 130 and 160 may comprise, any acceptable polymer adhesive as
is known in
the art, such as copolymers.
4
CA 02714872 2013-02-22
In addition, layers 120 and 140 may be bonded by the addition of additives to
the layers, by
way of example only, 2,5-furandione, the chemical structure of which is set
forth as Formula 1 below:
0
0 0 (1),
when added to the layers may cause the layers to become bonded together
without the need for
additional adhesives.
The layers are typically coextruded through a specially designed extrusion die
head using
multiple extruders. The melted polymer layers are then cooled into one
continuous seemless tube.
For a rod pumping system 10 (see FIG. 3) commonly referred to as a beam
pumping well,
using a plurality of sucker rods 20 (see FIG. 3) disposed within a string of
tubing 24 which extends
into said well, said string of tubing comprising a plurality of tubing
sections each having a bore and an
inside diameter; a down hole pump 28 operably connected to said sucker rods
20; and means for
reciprocating said sucker rods wherein the improved method comprises using
tubing sections having
polyolefin liners disposed within said bore of said tubing sections to
eliminate contact between said
sucker rods and said tubing string when said sucker rods are being
reciprocated.
For a rotating rod pumping system 10 (see FIG. 3) commonly referred to as a
progressive
cavity pumping system, using a plurality of sucker rods 20 (see FIG. 3)
disposed within a string of
tubing 24 which extends into said well, said string of tubing comprising a
plurality of tubing sections
each having a bore and an inside diameter; a down hole pump 28 operably
connected to said sucker
rods 20; and means for rotating said sucker rods wherein the improved method
comprises using tubing
sections having polyolefin liners disposed within said bore of said tubing
sections to eliminate contact
between said sucker rods and said tubing string when said sucker rods are
being rotated.
The scope of the claims should not be limited by the preferred embodiments set
forth in the
examples, but should be given the broadest purposive construction consistent
with the description as a
5
CA 02714872 2013-02-22
whole. By way of example only, the friction and wear reducing layer may
comprise nucleated
polypropylene; polyolefins containing nanocomposites or other additives to
control diffusion rates;
impact copolymer grade polypropylene; homopolymer grade polypropylene;
heterophasic copolymers;
fractional melt grade polypropylene; other thermoplastics coextruded with
polypropylene; reactor
made thermoplastic polyolefins; metallocene catalyzed polypropylenes; random
copolymer
polypropylenes; blends, alloys, filled or reinforced polypropylene or
polyethylene containing other
polyolefins and structural reinforcement. In addition, additives may be
included in the polymer to
increase the lubricity of the liner material and decrease the coefficient of
friction of the product.
The gas diffusion barrier may comprise other polymers, organic or inorganic
materials, or
metals. In some embodiments, this barrier is chosen to reduce or eliminate the
permeation of carbon
dioxide through liners utilized in CO2 floods and WAG (water-alternating-gas)
injection systems for
oil production enhanced recovery operations.
In embodiments in which the friction wear reducing layer and the diffusion
barrier are
chemically bonded 2,5-furandione or other similar additives may be used. The
layers may also be
bound by any acceptable adhesive as is known in the art. For example, an
acceptable adhesive may
comprise a copolymer. It is also envisioned that the friction wear reducing
layer and the diffusion
barrier need not be directly bonded together. There may be intermediate layers
between the two.
Additionally, there may be layers radially outward or inward of the diffusion
barrier. By way of
example only, the diffusion barrier may be sandwiched between the friction and
wear reducing layer
and a third layer. The third layer may be of the same or different material as
the friction and wear
reducing layer.
6
